Jeremy Katz of Red Hat reported that his iSeries machine would not boot
with 2.6.7 based kernels.

It appears that with the inclusion of Paul Mackerras' patch "Optimize
exception/syscall entry/exit" a small previous patch got reverted.  Here
is that patch again.  The lack of this patch does not stop all iSeries
machines booting, but it does stop some.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>